Effects of a month-long napping regimen in older individuals

To examine the effects of a month-long nap regimen using one of two durations (45 minutes or 2 hours) on nighttime sleep and waking function in a group of healthy older participants and to assess the degree to which healthy older individuals are willing and able to adhere to such napping regimens.

Three laboratory sessions, with 2-week at-home recording interspersed, using a between-participants approach.

Laboratory of Human Chronobiology at Weill Cornell Medical College and participants' homes.

Twenty-two healthy men and women aged 50 to 88 (mean 70).

Polysomnography (sleep electroencephalography), actigraphy, sleep diaries, neurobehavioral performance, sleep latency tests.

With the exception of adherence to the protocol, there were few differences between short and long nap conditions. Napping had no negative effect on subsequent nighttime sleep quality or duration, resulting in a significant increase in 24-hour sleep amounts. Such increased sleep was associated with enhanced cognitive performance but had no effect on simple reaction time. Participants were generally able to adhere better to the 45-minute than the 2-hour nap regimen.

A month-long, daily nap regimen may enhance waking function without negatively affecting nighttime sleep. Using 2-hour naps in such a regimen is unlikely to meet with acceptable adherence; a regimen of daily 1-hour naps may be more desirable for effectiveness and adherence.